In general, a vehicle has room light which is disposed nearly on the center of the ceiling thereof in order to illuminate the whole of the cabin of the vehicle, and which is made to be switched on or off according to a passenger's switching operation or opening or closing of a door. Since such a vehicle cabin lighting apparatus aims at lighting the interior of a vehicle cabin at night or the like, the lightness and hue of light emitted out of the vehicle cabin lighting apparatus are fixed and it is not necessary to change them in particular.
There have been proposed, as related art vehicle cabin lighting apparatus, a display for displaying information on the operation of a vehicle which is disposed in the cabin ceiling of the vehicle so that the driver on the driver's seat can visually recognize an image displayed on the display via a reflecting mirror placed in the front of the driver's seat (for example, refer to patent reference 1), and a monitor display apparatus for vehicle-mounted camera which is used for lighting the vicinity of the driver's seat (for example, refer to patent reference 2).
[Patent reference 1] JP, 6-35801, Y
[Patent reference 2] JP, 7-17647, U
A problem with the above-mentioned related art vehicle cabin lighting apparatus is, however, that since they aim at lighting the interior of a vehicle cabin at night or the like, and the lightness and hue of light emitted out of the vehicle cabin lighting apparatus are fixed and it is not necessary to change them in particular, they cannot structurally emit light having an arbitrary amount falling within a variable range and an arbitrary tone, and, even in the case of above-mentioned patent references 1 and 2, since they simply make it possible for the driver to visually recognize an image displayed on a display for displaying information on the operation of the vehicle via a reflecting mirror placed in the front of the driver's seat, or simply use the light emitted out of the display for lighting the vicinity of the driver's seat, they cannot structurally and effectively use the image light from the monitor (e.g., a liquid crystal display) mounted to the ceiling of the vehicle for lighting the cabin of the vehicle.
The present invention is made in order to solve the above-mentioned problem, and it is therefore an object of the present invention to provide a vehicle cabin lighting apparatus which can light the whole of a vehicle cabin and can emit light having an arbitrary amount falling within a variable range and an arbitrary tone so as to provide lighting representation which is in agreement with passengers'feelings or the atmosphere of the cabin for the passengers, and which can also change the light pattern, light color, or the like according to the status of the vehicle so that the vehicle cabin lighting apparatus can serve as an alarm and safety apparatus which notifies the status of the vehicle to the passengers in the cabin and persons outside the cabin.